


Deductions and Magic

by ThestralWolfsbane (Sentra04)



Category: Harry Potter - J. K. Rowling, Sherlock (TV)
Genre: Alternate Universe - Fusion, Alternate Universe - Magic, Gen, Magic, Post - Deathly Hallows, Witches, Wizards, past-hurt!Watson
Language: English
Status: In-Progress
Published: 2012-06-10
Updated: 2013-05-30
Packaged: 2017-11-07 10:31:20
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 4
Words: 6,132
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/430075
Author URL: https://archiveofourown.org/users/Sentra04/pseuds/ThestralWolfsbane
Summary: <blockquote class="userstuff">
              <p>So when Mike Stamford came to his borrowed lab with another man, Sherlock didn't realize just how much the old school mate of his still had his interest at heart. Mike had been a mentor of sorts to him at Hogwarts. A Ravenclaw, like himself, but a year ahead of him. While Sherlock didn't exactly need the schooling help - Mike had been a quiet force to helping him navigate the social norms that he just couldn't fathom. "Bit different from my day." He was telling the stranger that trailed behind him, the heavy tap of his cane too loud in the still lab.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> much of the beginning dialog has been modified, but comes directly from the episode I don't plan on doing this often - but... i'm not as brilliant as Sherlock, or the BBC Writers, and have to cheat sometimes.
> 
> Sorry....
> 
> Doesn't not take place with the potter cast - same names may bleed over - but the positions have greedily been snatched up by members of the bbc!sherlock crew... at least for the time being.

No one had before survived the Killing Curse. At least not to Sherlock's vast recollection.

It wouldn't be much of a killing curse if there were survivors - and if it couldn't guarantee death - most would likely find it not worth the risk to perform it. Naturally, when his network had told him such a survivor did exist, he'd carefully cataloged it away as unlikely - but something he'd like to investigate further, should the opportunity arise.

So when Mike Stamford came to his borrowed lab with another man, Sherlock didn't realize just how much the old school mate of his still had his interest at heart. Mike had been a mentor of sorts to him at Hogwarts. A Ravenclaw, like himself, but a year ahead of him. While Sherlock didn't exactly need the schooling help - Mike had been a quiet force to helping him navigate the social norms that he just couldn't fathom. "Bit different from my day." He was telling the stranger that trailed behind him, the heavy tap of his cane too loud in the still lab.

"Mike, can I borrow your wand?" He'd only mentioned to the the wizard a day ago what a nightmare he must be to share a flat with, and here Mike was with a down-on-his-luck Wizard, clearly in need of a roof over his head. 

"And what's wrong with yours?" he asked, voice hinting amusement, but making no move to help Sherlock in his request.

"I left it in my coat."

"Here, use mine." He held himself rigid, and ready, like a battle worn soldier- right hand extended, wand hilt towards Sherlock. Koa wood, a bit springy, 10 inches, core unknown. Too easily surrendered, and too old to originally belong to him. Sherlock knew all of the Aurors by name and face (if not personally) and the man was not one of them. Department of Magical Law Enforcement, or more likely Department of Security. Most likely a Hit Wizard. Uncertain though - the man truly carried himself like an Auror. A not-Auror who depended heavily on a cane and whose injuries to the left side had crippled and invalidated him.

"This is an old friend of mine, John Watson." Mike said, self assured smirk in place. Sherlock cast a spell on his memo to Lestrade; I.D. and watched the folded paper send itself off though the air.

"Dept. of Law Enforcement, or Security?"

Soldier Watson, blinked at him, "Sorry?"

"Which was it, Dept. of Law Enforcement, or Dept. of Security?" He asked again, handing the wand back.

"Dept. of Security, sorry, how did you know?" Soldier John asked, face equal parts curious and and worried. 

Molly chose this moment to slide in the room, slinking past Mike, and bring Sherlock the coffee he'd talked her into fetching for him earlier. "Ah! Coffee, thank you." She'd been four years under him at Hogwarts, Ravenclaw like himself, and a shadow he'd never really shaken off. But she didn't ask stupid question, and she never made unfounded statements, and Sherlock had grown accustomed in many ways to the fact she was usually there. He slipped the coffee, then glanced back at her, "What happened to the lipstick?" She had some one before - refreshed it even, and now it was nothing but her plain features again.

"It wasn't working for me." There was a note of resignation in her voice. His eyebrows knitted, searching for an explanation for it.

None really came to mind, "Oh. Really? It was an improvement. Your mouth's.... too small now."

While it maybe wasn't the wrong thing to say; it certainly didn't seem to be the right thing, because she just hung head and sighed out an "OK."

Sherlock didn't know what he should be saying, so he settled for nothing at all, glancing back to the still smirking Mike and the not-Auror from the Department of Security. "How do you feel about the violin?"

The poor man looked out of sorts, "I'm sorry, what?" and Sherlock wondered about Mike's judgment. Still - he was a man that likely would mind his own business, and for the time being, Sherlock would indulge his former Housemate. Mike didn't like Sherlock living off on his own.

"I play the violin when I'm thinking and sometimes I don't talk for days on end. Would that bother you?" There was nothing but a blank look, and Sherlock was quickly coming to the conclusion that this again wasn't going to work. He hated to have to break it to Mike in a few days, but it was bound to happen, "Potential flatmates should know the worst about each other." he spelled out for the man.

In turn, Watson just look back at Mike in accusation, "You told him about me?"

"Not a word." The man grinned, clearly enjoying himself. Sherlock used to wonder how it came to be the two of them came to be ‘friends,’ but his blatant amusement spelled it out clearly. Sherlock could only just restrain the eyeroll.

"Who said anything about flatmates?"

"I did. Told Mike yesterday that I must be a difficult man to find a flatmate for." He shrugged. It was true, though Sherlock felt he was hardly the one to put entirely to blame, "Now here he is just after lunch with an old friend clearly just home from military service of sorts. Wasn't a difficult leap."

"The Department of Security, yeah. How'd you guess?"

"Got my eye on a nice little place in central London." The statement didn't need validating, Sherlock was tired of correcting people, so Sherlock plowed on, "We ought to be able to afford it. We'll meet there tomorrow evening, seven o'clock."

He was to the door then, checking the time. He wanted to check back in with Lestrade, "Sorry, got to dash. I think I left my riding crop in the mortuary."

Watson however wasn't to be brushed off, "Is that it?"

"Is that what?"

"We've only just met and we're going to go and look at a flat?"

Sherlock blinked, "Problem?"

There, finally, was movement to John's face - Real movement - frustration being the most pronounced, "We don't know a thing about each other. I don't know where we're meeting, I don't even know your name!"

Molly and Mike both had private smiles, and Sherlock beamed, preening a little as he showed off, "I know you're a Healer, likely a Mediwizard and you've been relieved of your duties with the Department of Security.  
"You've got family worried about you, likely an older brother but you won't go to him for help. You where a Gryffindor Student, extremely high marks in DADA, And I know that you're mixed blood, magical parent deceased, but they were superb Charm casters.  
"That's enough to be going on with, don't you think?" Satisfied with his deductions, be pulled his scarf tight and made his way again to the door, "The name's Sherlock Holmes and the address is 221B Baker Street."

"Yeah, he's always like that." He pretended not to hear and he headed down the hall.

**Notes for the Chapter:**

> Lestrade I.D. (Investigation Department; The Investigation Department was a subdivision of the Auror Office. It centered on investigation and tracking down dark wizards. Still with the Dept. of Magical Law Enforcement.)
> 
>  
> 
> it was really hard to figure where to put John - since the MOM doesn't really have a military. I wanted to leave Lestrade and NSY to the Dept. of magical Law, but the auror's are a specially trained class, and while i think John's long term goal was to be there - i imagined he'd focused more on the medical side - hence the medi-wizard.


	2. Chapter 2

As far as the muggles of 220 and 222 Baker Street are concerned, 221 is a single apartment owned by widow Mrs. Hudson. The polite and law abiding wizards of London believe that there are three apartments here, owned by ex-wife of Death Eater Rowanton Hudson. Martha Hudson lives in 221A, and rents out 221B to the younger (if somewhat unstable) brother of MoM Official Mycroft Holmes, and 221C to Mr and Mrs Tinyforth (a young couple - both muggleborn - who'd been left disabled after the wizard war). The more 'worldwise' wizards know better. 221 has at least 18 apartments, and Mycroft Holmes had no hand whatsoever in getting his baby brother such a posh location. 

No - the 'consulting auror' as he fancied himself - had single handedly proved Rowanton Hudson as a death eater, and had ensured the man a lifelong term at Azkaban. Martha Hudson had been so grateful she'd pretty much given him the apartment. Actually, most of the tennets where there nearly rent free.

Most were wizards that the MoM had deemed unsavory, but could not prove anything against. Holmes the Younger had subtly given Mrs. Hudson the nod on them, assuring her that no matter how questionable they were - they would not harm her. At least not intentionally. It was a rather accident prone and thrill seeking group, but overall harmless.

A dozen Daily Prophets, and a few muggle papers spread in pieces across the living area of the flat in 221B. Sherlock Holmes had one corner with a fairly new laptop running, charms and wards carefully placed around it to null the magic enough for the electronic machine to pull information from the muggle world wide web. The internet was one of the things that fascinated young Sherlock Holmes to no end. He'd done hundreds of experiments over the past few years to try and combine magic with the computer to at least keep it running without all the precautions, the vast majority of them failing spectacularly. Texting was the other. 

Oh... how he would love to make texting work.... He'd been playing with mobiles since the early 90's. It had taken him less then half an hour to completely destroy his first phone, much to his brother's annoyance (it had been one of the few gifts that either brother had bother to remember, and it was never to be brought up again)

As it was, he had to settle on charmed memo's and the occasional mirror. He was still trying to convince I.D. Lestrade to carry an enchanted coin, or some similar protean charmed object, but the man'd only smirked, and handed him the two-way mirror. 

A chime sounded - someone was looking at the flat (Someone besides his overbearing arch-nemesis, who Sherlock was regretful to admit was *always* watching). Peaking out the enchanted window, he saw Soldier Watson across the street.

He was still as harried looking as yesterday - a man who slept to little (Sherlock was extremely familiar to that state) and got no rest when he did. Too guarded and wary. Like most of Mike Stamford's company of late - he was likely one of the Wizards ostracized by the MoM beginning under Thicknesse's disastrous short reign. But outside of the wizard's corner of the city, Watson had forgone his robes, and blended in to the London muggle backdrop in faded ill-fitted second hand muggle layers. When traffic slowed, he limped across the street, cane marking his progress as Sherlock headed to the door to meet him.

Mrs. Hudson was just coming out of her own room, likely having been tracking the man since the chime originally sounded. Sherlock smirked, stepping around her with ease and slipping out the door, "Hello~!"

"M... Mr. Holmes." He looked uneasy, shifty weight from side to side, right hand tight on the cane. 

In turn, Sherlock made a face, "Gah. Sherlock, Please." cringing as the title filled his head with ill-memories of his own father.

The wizard nodded, looking up the building; Sherlock could see him judging the true layout, mental picking the charms apart to map out the rooms and floorplans. Sherlock wondered how many rooms he could sense just by the outside glance. "It's a prime spot..." There was a wariness in his voice; Sherlock could see him crunching numbers in his head, could see the way his shoulders stiffened when the numbers didn't end in his favor.

"Mrs. Hudson, she's the landlady - she's given me a special deal." She was smiling at his side in the doorway, but small details about Watson where starting to jump out, and Sherlock found his monologue loosing steam, "...Owes me a favour. A few years back, her husband got himself sent to Azkaban.... I was able to... help out.... "

Mrs. Hudson 'shushed' him, lightly smacking his elbow, but he attention was solely on the wizard in front of him. "Mrs. Hudson, MediWizard John Watson...."

"Hello. Come in, Dear." She smiled, pulling Sherlock out of the doorway to allow the wizard to enter the building. Watson paused, glancing up to the stairs and stairs squeezed into the narrow hall, crossing back and forth up and down multiple levels.

"How many apartments?" Sherlock asked, and Mrs. Hudson paused on the stairs to look back curiously. She was the only one who knew for certain how many rooms there where, and much to the annoyance to Sherlock, it was one of the few things he'd been unable to deduce from her.

"Uh.. Twenty? At least... "

She chuckled, before continuing up the stairs. "Shall we?" Sherlock studied him; more little things jumping out, waiting for Sherlock to form them together for the complete story.

The flat was already quite cluttered from Sherlock, but he'd made an effort to clean out the top floor last night when he'd returned from his meeting with Lestrade. Watson seemed a little put out by the mess, _Pity...._ , but said nothing. Well, nothing about the mess, "That's a skull."

"Friend of mine. When I say friend..." he trailed off. There it was! The man's left arm was held stiffly, and never seemed to leave his pocket. Under the robes, it wasn't so noticeable, the shoulder having dropped off a few inches sooner on the left than the right - but it was hard to tell with dark colours. But his right leg was the one with the limp - so his left hand should have held the cane. The only reason that came immediately to mind is that it was a new injury (would have to be, a permanent and older injury would have resulted in a merge of wand and cane, which the wizard had yet to do....) But Watson had used his right hand to hand over his wand, had kept his left side out of sight.

Mrs. Hudson and he where discussing the bedroom upstairs, and it took all of his willpower to wait until she'd wandered out of earshot. "...When did you loose your arm?"

Watson's whole body tensed, and when he looked Sherlock in the eye, the gaze was cold, hard, and brutal. "1997. August."

"The coup on the Ministry of Magic...."

"Yeah."

That wasn't all though, still little flags waving, and Sherlock once again reassessed the man in front of him. Taking back in the secondhand wand, and the limp. The reason he couldn't pinpoint the man's profession.

"What about these suicides then, Sherlock?" Mrs. Husdon murdered, reentering the room. They quietly screamed off the pages of the Daily Prophets on the table as she stood looking down at them. "I thought that'd be right up your street. Three exactly the same."

The chime sounded again, and Sherlock darted to his window, looking out on the street, declaring, "Four. There's been a fourth. And there's something different this time."

Watson moved around to read the papers intently, as Mrs. Hudson stiffened, "A fourth?"

Still studying the window, Sherlock ignored her, asking the man now in his doorway, "Where?"

Auror Lestrade from the Investigation Department looked steadily back, "Brixton, Lauriston Gardens."

He mapped it out in his head, turning information over and over in his mind, "What's new about this one?" Sherlock turned away from the glace, reading into Lestrade stance, "You wouldn't have come to me otherwise."

The grim smirk was back, the look of self hate on Lestrade's face that said his group had found themselves once again in need of help, "You know how they never leave notes?"

"Yeah." 

"Well, This one did." The smirk was gone, face honest and weary, "Will you come?"

Sherlock ran over Lestrade's team in his head, frowning. They wouldn't do- and he really did prefer to have a sounding board. He doubted the skull would be welcome... Lestrade sighed, asking again, "Will you come?"

"Not with you, but I'll be right behind." He confirmed. There was a public floo not to far, would be one of the quickest ways, only a few block by foot.

Lestrade nodded, looking grateful, with a "Thank you," before departing back outside to apperate.

As soon as the man had gone, Sherlock beamed, "Brilliant! Yes! Four serial suicides, and now a note!" moving about the room to gather his coat and scarf with a smile spreading ear to ear. "Oh, it's Christmas. Mrs Hudson, I'll be late. Might need some food!"

The witch gave a long suffering sigh, "I'm your landlady, dear, not your housekeeper."

"Something cold will do." He grinned at her, dropping floo powered into his fireplace, "John, have a cup of tea, make yourself at home. Don't wait up! Lauriston Gardens!" He stated, stepping into the green flame.

He stepped out into Brixton, when he thought better of it. His own fireplace was one way, but the shop on street level two doors down wasn't, so he jumped back, and ran back to the flat.

Mrs. Hudson was just leaving, "Not your housekeeper!" as he ran up the steps, bursting back though the door to his flat.

"You are a Healer. In fact you're an MediWizard."

Watson had sat down at some point, as if to take a moment to organize his own thoughts, but he looked at Sherlock level, before nodding. "Yes."

"Any good?"

John Watson sat straight, proud. "Very good."

"Seen a lot of injuries, then. Violent deaths?"

His face was guarded, calculating,"Well, yes."

"Bit of trouble too, I bet?" It was hard not to invade the man's space, to crowd him in anxious anticipation.

"Of course. Yes." He frowned then, conflicted, "Enough for a lifetime, far too much."

"Want to see some more?" Sherlock called his bluff, refraining from punching the air on by a hair when he looked up - twin looks of delight on both their faces. 

"Oh, Merlin's Beard, yes!"*

**Notes for the Chapter:**

> Some timeline notes:  
> Lord Voldemort's takeover was on 1 August, 1997. the Muggle-Born Registration Commission was started in September of '97 and was in effect until 2 May, 1998.
> 
> Canonly, Harry Watson is 36 in 2010. This would make her her 23 in 1997. She's the only character I have found a definite age for in the bbc!Sherlock. Using this I'm going to place this story in happening in early 2000. The characters are a decade younger than the bbc!show - but i wanted to work with the aftermath of the 2nd Wizard War. They still ended up a bit younger than i would have liked. Regardless - tentative ages for sherlock and john are 19/20ish during the takeover in 1997 and 22/23ish currently.


	3. Chapter 3

Stepping out of the fireplace with a nod to the store's owner (Slytherin house - nine years Sherlock's senior. Excelled in Runes and Charms. Sycamore wand, springy, 7 and 3/4 inches, with Pegasus feather core and ornately carved) Sherlock glanced at Watson as he looked out on the Brixton street to get his bearings. "You have questions." Not a question itself. Just a statement of fact.

"Yeah," The shorter wizard nodded, falling in pace with Sherlock (with the click, click, click of the cane matching every other footfall), "Where are we going?"

"Crime scene." Not exactly the question Sherlock was expecting first, and it made his hurry to suppress a smirk. "Next?"

"Who are you?" Despite the height difference, Watson looked at him in away that felt as if he was looking down and studying Sherlock in turn. "What do you do?"

"What do you think?" Mike had a marvelous insight into people, and Sherlock would admit, begrudgingly so, that the wizard that he'd introduced to him was an amusing sort of puzzle himself. He didn't outright shy away from Sherlock, and in turn, Sherlock found him not terribly dull.

"A Legilimens. But that's not right. If this was a fantasy muggle story of sorts, I'd say...private detective."

He actually had to stop and look at Watson with that one. It was not even close to the first time he was accused of skill in _legilimency_ , but It was the first time that someone dismissed the notion so outright.

"I'm a consulting Auror. Only one in the world, I invented the job."

In turn, Watson held his gaze, and Sherlock watched him ponder it over. "What does that even mean?"

He smirked, turning back to the sidewalk and gliding smoothly down the walk. The click, click followed him, "It means when the Investigation Department are out of their depth, which is always, they consult me."

"The Auror Office doesn't consult..." He trails off, and Sherlock has to keep the bounce from his steps and he turns to face the man, smoothly striding backwards down the walk.

"When I met you for the first time yesterday, I asked Department of Law Enforcement, or Security."

John Watson frowned, the lines on his forehead, and around his eyes deepening, "Yes, how DID you know?"

"I didn't know, I saw." Watson raises an eyebrow, but lefts Sherlock explain. "Your haircut, the way you hold yourself says discipline, combat training. When Mike and you first entered the lab _'Bit different from my day'_ said trained at Barts - so Mediwizard. A standard Healer would of studied at Mungos. So. MediWizard, with combat training. Law Enforcement or Security. 

"Your limp's really bad when you walk, but you don't ask for a chair when you stand, and you've yet to combine your wand and cane. Sometimes, you forget that it suppose to hurt, and it's never come to mind when you've had to defend yourself with your wand. That says the original circumstances of the injury were traumatic - wounded in action then, and relieved of your duties with the Department of Security. With the arm injury," He rolled those thoughts around, fitting the newer discovery into his first observations, looking them over to how they fit. He allowed the line of thoughts trail off as he studied Watson's face. It was guarded and distant, and the wizard still hurt just thinking about that event. _Traumatic._

"You knew some about my family," John said finally, as the turn the street, the crime scenes' yellow tape bright at the end of the next intersection.

"Your wand. Koa, 10 and 3/4 inches long and reasonably springy, with likely a pegasus feather core. A good wandfor Charms work. It is somewhat darkly colored and is intricately carved. It's finicky at the best of times, didn't really want to work for me at all, and it really doesn't feel much loyalty to you either. But it finds a kindship to you, likely belongs to a family member, most likely a parent, so it tolerates you. If it's owner was still alive, it wouldn't at all. 

"Most people are buried with their wands, but after Ollivander's attack during the Coup and the Muggle-Born Registration Commission, wands got scarce, and some people got desperate. Mostly those who falsely lost theirs during the trails. Grave theft was for the desperate. You were hurt, badly, and someone made sure you could defend yourself. A muggle wouldn't have understood your need for a wand - so a wizard in the family. Could be a cousin, but you who can't find a place to live - it's unlikely you've got an extended family, not one you're close to. So sibling it is. They felt the need to do something as terribly as grave robbery, they felt they had to take care of you, an Older brother, feeling guilty you got hurt in the first place."

The look on John's face is open and dumbstruck. He's stopped walking at this point, and just openly stared. Preening, Sherlock allowed himself to smirk, "You a MediWizard, who was employed by the Department of Security. Courageous and Brave. You'd have to be good at DADA for both positions, but you! No, you were Gryffindor, you held yourself to confidently, you handed over your wand with ease because you have no fear of me, at all. Extremely high marks in DADA."

"That...was amazing."

Sherlock felt his smirk slip, and looked down on John curiously. "Do you think so?"

"Of course it was. It was extraordinary, it was quite extraordinary!"

Sherlock blinked rapidly, looked away and turned this over and over in his head, "That's not what people normally say."

"What do people normally say?"

The smile is back, not so much posturing, more sincere, " 'Piss off.' ...."

They said nothing more as they closed the distance between them and the crime scene. Just before the got in ear shot of the Aurors on scene, Sherlock held up a hand, not quite touching John, bring them to a pause "Did I get anything wrong?"

He smirked, "Dad was muggle, passed on before I really got a good idea of who he was. Mum was a Gryffindor, good at charms and on the lucky side. She died right after I graduated Hogwarts. This wand was hers, and Harry dug it up after... Everything... Harry and me don't get on, never have, but.. it was nice gesture."

That preening look was back and Sherlock grinned, "Spot on, then. I didn't expect to be right about everything."

But John's smirk remained, "Harry's short for Harriet. She's a muggle, not an once of magic. And I was a Hufflepuff."

"Huffle... Harry's your sister?"

He just shrugged, looking to the crime scene where one of the Aurors standing guard was looking them over, "Look, what exactly am I supposed to be doing here?"

"Sister!"

"No - seriously, what am I doing here?"

Sherlock ignored him, re-evaluating the facts, letting the tumble around in his mind, "There's always something...." as he walked forward, John Watson trailing uncertainly, but unwavering, behind him.

**Notes for the Chapter:**

> I used [ Springhole's Magic Wand Generator](http://www.springhole.net/writing_roleplaying_randomators/magicwand.htm) to help figure out some of the wands for this. Some things I *knew* i wanted for some of the lead characters, but it was such a valuable resource.


	4. arch-enemies and the alarming use of the colour pink

**Notes for the Chapter:**

> sorry for the delay - i got stuck on this part for a long time... a LONG time. so many different re-writes on how to approach first contact with the killer; all of them worse then the last, until this.
> 
> i'm *Still* not happy with how reliant my story is on bbc!dialogue, and i do have later sections veering off much better - but getting from here to there has been hard, and actually writing out conversations has never been my strong suit. Actions are so much easier for me to write then verbal exchanges.  
> So i do very much apologize on how painful it might be for some to read, with the exchange being to blatantly unoriginal.

The common rooms of the tiny flat where busy with streams of magic - information constantly moving in threads through the living room to kitchen and back, as Sherlock Holmes stood silently, hands partially raised, in the middle of it all.  
  
He didn't move, didn't acknowledge John’s entrance in the slightest, eyes darting madly back and forth, fingers ticking off information only he could fathom, as he looked over the words in the air, moving only to occasionally dart to the rooms corner where his muggle laptop ran quietly, before studying the air again.  
  
Limping into the room, John could read most of the lines – some looked to be reciting the recent papers- but others seemed random, John unable to decipher their significance. What appeared to be a weather map formed briefly in the air between kitchen and door to the hall, before fading out when Sherlock looked away.  
  
So, he waited, watching the manic Sherlock Holmes dance around his spells, before finally clearing his throat and holding up a blank paper. “Found this in my pocket.”  
  
When Sherlock turned to regard both it and John Watson, he could see his handwriting echoing back from the card, his sprawling script writing out a short message before fading away; ‘Come if convenient’  
  
“Well...? You asked me to come, I'm assuming it's important.” So impatient Watson was, holding up the card as Sherlock’s message continued, ‘If inconvenient, come all the same’  
  
“I need you to cast a tracking spell.”  
  
If anything, John Watson’s shoulders straightened even more, and Sherlock watched him recompose his calm façade. “Cast a spell?”  
  
“Always a chance my magic signature will be recognized; I called for Ms. Hudson,” as if it explained everything, and then Sherlock turned away, a curl in the text before him catching his attention, trailing off with a, “...but she didn't seem to hear me.”  
  
“Well, I *was* on the other side of London... remember, Lauriston Gardens.”  
  
“Just a floo away; Besides, there was no hurry.”  
  
“Just a-! Not ‘a floo away’ if you don’t know a single bloody wizard in Brixton…” It was muttered under his breath to be fair, but Sherlock smirked all the same. But only because he currently had his back turned to the man.  
  
John pulled his wand from inside his jacket, fingers holding the wood lightly, unsure. “So what's this about – the case?”  
  
“Well, Her case...” Sherlock clarified, moving to stand with his back to the book case, one eye watching John try to work over his own conclusions for the body in Lauriston Gardens and the other skimming his news feeds.  
  
John didn't seem to be following though, “ **Her** case?” and Sherlock was disappointed the man hadn't reached the same conclusion he had.  
  
“It's no use, there's no other way. We'll have to risk it.” Sherlock murmured, waving his own wand dismissively at the spells in the air, the text falling apart like dust on a sunbeam.  
  
John gave him an annoyed look; more than annoyed: unsettled. It wasn't that he’d been summoned to do spellwork for Sherlock, there was something else. “What's wrong?”  
  
John tapped the tip to the table, moving to find the best way to hold the utensil with his non-dominant hand, struggling to find that natural feel that he was still lacking “Just met a friend of yours.”  
  
Sherlock looked at him in alarm, mind drawing a complete blank, and his throat going dry at the lost sensation –“A friend?”  
  
Hand finally comfortable with its grip, rolling the wand between his fingers, John looked up at him, face collected, but far from blank. Distant, thoughtful; “An enemy” He amended.  
  
“Oh.” That was a more comfortable idea – Sherlock had plenty of those, and knew how to deal with each one appropriately, “Which one?” He asked, dropping down on the couch causally, kicking his long legs up over the arm, before casually looking over at his flatmate.  
  
“Well, your arch-enemy, according to him.” His face was a picture of pure pondering; amazing how open was the face of the once soldier, “Do people have arch-enemies?”  
  
Schooling his own face in response to John’s openness, Sherlock thought on his meddling brother, “Did he offer you money to spy on me?”  
  
“Yes.”  
  
There was no hesitation, no playing with the idea, and the frankness of the answer surprised him again. Maybe John Watson couldn't figure out the now obvious connection with the missing bag, and the clever pink woman, but still – he was so different, that Sherlock honestly didn't yet know what to make of it, “Did you take it?”  
  
“No.”  
  
“Pity, we could have split the fee." Indeed. How could a man like John Watson exist?! "Think it through next time.”  
  
John looked thoughtful, honest curiosity on his features, “Who is he?”  
  
“The most dangerous man you've ever met,” Sherlock wondered how his brother had treated the man before him – what attempts he’d used to get under his new flatmate’s skin. It had unnerved Watson, but had not shaken him. “…and not my problem right now. Now, the spell. Jennifer Wilson”  
  
Either John did not believe Sherlock’s claim, or his interactions with past dangerous men had left him numb and unfeeling to such men. Sherlock fancied it to be the latter. “Jennifer Wilson.” He cleared his mind, before pinning Sherlock with a sharp look, “That was... Hang on! Wasn't that the dead woman?”  
  
“That's not important.” At John’s look, he amended, “Yes.” Moving quickly to perch on the arm of his chair, Sherlock mentally rehearsing his findings. “The wand is made of fig wood and has a core of unicorn hair. It is 11 inches long and is inflexible. It is of a medium tone and is intricately carved. Likely pink charm on it.”  
  
“ _Reperio Jennifer Wilson_ ” John cast, imprinting the image Sherlock had described with the face from the corpse this morning in his mind. He made a small grunt, as the spell sought out the late witch’s wand, pulling the koa wood in his hand harshly to the right.  
  
When he opened his eyes to show Sherlock, he found instead his flatmate pulling a small pick case out from under the chair. He seemed to be beaming, as he looked up to see John’s wand pointing out to the street.  
  
“That's... That's the pink lady's case, that's Jennifer Wilson's case!”  
  
Sherlock’s smirk was patronizing at best, “Yes, obviously. Oh, perhaps I should mention - I didn't kill her. Now, her wand – let it know to find you!”  
  
John Watson closed his eyes with a “I never said you did,” as he pictured Wilson and her wand again. “ _Reperio mihi_ ”  
  
The itch in his wrist ached a little - no doubt the wand in question was turning where if was to point back at John. There was an uneasy quiet threatening to fall; John hefted his wand, wincing at the heavy, itchy feeling it was leaving in his wrist. _Magic signature indeed_ he mulled, sure the only reason Sherlock hadn't done it himself was to escape the uncomfortable effects now making themselves known “So... How did you get this then?” he asked, waving at the case.  
  
Sherlock smirked, and began waving his own wand, wards and protection spells glowing faintly along the walls. The itch in John’s wrist lighted dramatically, “By looking.”  
  
John flexed his fingers around his wand, waiting for the excited man to continue. He didn't have to wait long, Sherlock grinning as he shuffled through the late woman’s belongings.  
  
“Her killer must have driven her to Lauriston Gardens. There was no trace of them in the floo; unlikely to have persuaded her onto a broom; and apparating with a likely wary hostage would've been exceedingly dangerous. Besides, he could only keep her case by accident if it was in the car. Nobody could be seen with this case without drawing attention - particularly a man, which is statistically more likely. So obviously he'd feel compelled to get rid of it. Wouldn't have taken him more than five minutes to realize his mistake. I checked every backstreet wide enough for a car five minutes from Lauriston Gardens, and anywhere you could dispose of a bulky object without being observed. Why risk magic if you don’t need too. Why risk a trace if it’s not needed. Took me less than an hour to find the right skip.”  
  
“Pink.” John said finally, “You got all that because you realized the case would be pink?”  
  
“It had to be pink, obviously.”  
  
Somewhat annoyed, John could keep the bite from his words “Oh, yes. Why didn't I think of that?!”  
  
“Because you're an idiot.” Sherlock said, trying his best to sound sympathetic. It clearly wasn't taken that way – the outright _hurt_ of John’s face enough to have Sherlock scrambling for words, “No, no, no, don't look like that! Practically everyone is!”  
  
He waved John to look at the open case, urged him to see, “Now, look. Do you see what's missing?”  
  
Unfortunately, John Watson was still reeling from Sherlock’s comment - because really, how could it be obvious a murderous wizard would be traipsing around in a muggle car, all because his victim had a pink case!! - and barely looked up before raging, “From the case?! How could I?!”  
  
“Her wand, John! Where's her wand?” He gestured frantically, disbelieving that John really didn't see it. Really, how could the man not? “There was no wand on the body; there's no wand in the case. The question is where is her wand NOW?”  
  
John’s answer of “She could have lost it.” Was weak in both their ears, and he looked thoughtfully back at Sherlock, the hurt gone.  
  
“Yes, or?” he prompted.  
  
“The murderer... You think the murderer still has her wand?” John looked in his hand, following the point of his wand out to the street.  
  
“Maybe she...left it when she left her case. Maybe he took it from her – there _is_ still a market for it, after all. Either way, the balance of probability is the murderer has her wand.” Sherlock move to stand by John, following his look out the window.  
  
“Have you talked to the Investigative Department?”  
  
Sherlock gave him a baleful look, “Four people are dead, there isn't time.”  
  
“So why are you talking to ME?”  
  
“Mrs. Hudson took my skull.” He pouted, but more playful and amused then actually sulking, moving away - and stepping on and over the coffee table - to pull his scarf from where it hung by the door.  
  
“So I'm basically filling in for your skull?”  
  
“Relax, you're doing fine,” He didn't care for the panicked, self doubting look on his flatmate’s face, “Well?”  
  
“Well, what?  
  
Sliding his coat on, Sherlock gestured to the couch, “Well - you could just sit there and...watch telly.” he suggested, his voice dripping with disdain at the idea.  
  
“What, you want me to come with you?” never mind the fact he was moving to Sherlock’s side without a thought to it.  
  
”I like company when I go out, and I think better when I talk aloud.” Sherlock found himself admitting honestly with a shrug, “The skull just attracts attention, so... Problem?”  
  
Again, John Watson surprised him, “Yeah, Sergeant Donovan.” And he said it so matter of fact that Sherlock didn't follow, just regarded him with raised eyebrows.  
  
“What about her?”  
  
“After you ran off. She stopped me.“ The first part was so accusatory, that Sherlock couldn't help the fidget, couldn't help but turned and sniff; “She said...you get off on this. You enjoy it.”  
  
“And I said ‘dangerous,’ and here you are.” Sherlock smirked, gesturing to wand still in John’s hand, still pointing them out into London’s darkness.  
It became a full blown smile, and he gently took John’s wand, sliding it with ease into the man’s breast pocket and handing him his cane. John’s ‘Damn it!’ was a wonderful mix of amused and exasperated, and he allowed Sherlock’s casual prodding of him out the door.

**Notes for the Chapter:**

> I took some liberties with the fandom’s tracking spell - changed it a little bit so it works with any wand, provided the holder hasn’t taken measure to prevent it. Seeing as Wilson is dead, there would be no blocks. see the original spell here: http://harrypotterfanon.wikia.com/wiki/Tracking_Spell
> 
> I am also running with the idea that magic is traceable to an extent, and each witch or wizard has their own signature when they cast spells. BUT!! they are much like fingerprints - unique, but still basically the same, and it can be quite a challenge to differentiate them from each other - especially when only getting a ‘partial’ print (from age of spell, or other factors)
> 
> Also - google documents keeps insisting that the last ‘wand’ in this chapter is wrong, and asks me if i meant ‘hand’  
> XD  
> really google docs? holding hands? already?


End file.
